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Check Charging System and Voltmeter readings fluctuate.

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1.3K views 2 replies 3 participants last post by  Buldawg76  
#1 ·
I have a 2015 Ecoboost premium with performance package. In last six weeks I have had the alarm 'Check Charging System' come on twice. Does anyone know what actually triggers this alarm? In each case I have put a trickle charger on as battery was low. The car does spend a lot of time not being used and it is possible there is an intermittent current leak.

When I take the car out and monitor the voltmeter I get 14.3 for first minute or so then it drops off to around 12.3 and seems to come intermittently to 14.3 and places in-between. Does anyone know if the car has a smart charging system and this is normal ? If not then, what else could cause this fluctuation ?

Alternator was changed by Ford dealership under warranty in around 2017, and the last battery change was about a year ago(I think it is about my 4th battery). An 'Autozone' test said battery, alternator and starter motor all passed. Tomorrow I start a trip out of town so bit concerned.
 
#3 ·
It does have a "battery management system" so yes it will vary charging on what it determines the need is but mine never gets below 13.0 volts while driving so not sure if 12.5 is a normal reading or not. A good battery at rest should read 12.6 volts and 13.5 on a maintenance charger in the fully charged float mode.

Not sure what triggers the alarm.

BD